Insects in burned forests — forest protection and faunal conservation (preliminary results)

摘要

The beetle colonization of fire-damaged trees was studied in seven reserves, which were established in burned forests in south and central Sweden, following extensive forest fires in the summer of 1992. In the spring of 1993, burned pine trees displayed a large range in fire damage from virtually undamaged ones to trees killed by the fire. Spruces were more sensitive than pine, and few fire-damaged spruces had some green foliage left. The pine shoot beetle, Tomicus piniperda (Linnaeus) was the main colonizer of pine trees, occurring at all sites, but altogether in only one-third of the trees. On spruce, two bark beetles were common: Polygraphus poligraphus (Linnaeus) was found on nearly all sites and altogether on half of the trees, followed in abundance by Pityogenes chalcographus (Linnaeus). These common species were accompanied by an assembly of bark and longhorn beetles, commonly occurring on fresh conifer timber. Most of the beetle species clearly preferred the dead or dying trees. However, the species mentioned above as well as Arhopalus rusticus (Linnaeus) also attacked trees with more than half of the foliage left. Three fire-favoured species were observed: Oxypteris (Melanophila) acuminata (Degeer), Sericoda (Agonum) quadripunctata (Degeer) and Pterostichus quadrifoveolatus (Letzner). Line surveys indicated little bark beetle dispersal from the burned areas into surrounding forests. Further studies are needed as the primary colonization of the burned trees was obviously not completed during this first year after the fire.